Disturbance Observer for Path-following Control of Autonomous Agricultural Vehicles

This paper proposes a disturbance observer to be integrated inside a path-following controller in order to improve motion accuracy of an autonomous driving tractor. During operation, the tractor undergoes the effects of external forces due to either the action of the implement or the inclination of the ground. In such conditions, it is difficult to work precisely along a pre-determined path. By considering external forces as disturbances, it is possible to design a disturbance observer that estimates the steering angle on the basis of yaw-rate and lateral velocity. The proposed approach has been tested in a simulation environment.